This invention relates to puzzles generally and more particularly relates to a manipulative disk type puzzle.
A disk type puzzle called the "Magic Disk" is shown and described in a book entitled "Creative Puzzles of the World" by Peter Van Delft and Jack Bartermans 1978, page 70 (Harry N. Abrams Inc., Publishers). This puzzle is in the form of three identical wooden disks which have been tri-sected and the sections glued together in a special pattern. The disks may then be fitted together to form a geometric solid which has the appearance of three stacked disks. With the three disks assembled, they cannot be pulled apart by any amount of pulling or tugging. Only a force applied in a certain way can separate the three components forming the stacked disks.
In order to separate the disks a shaft or pin may be placed in a hole in the center of the assembled disks and the disks spun with great force. The centrifugal force will cause the three components of the magic disk to separate and the components may then be completely separated by gently pulling them apart. Reassembling them is quite difficult, however, and requires a great deal of dexterity. The respective corners of the three parts have to be matched with the center of the hole in the other components and the disks carefully pushed together. Alternatively, the three disks may be separated by gently pushing alternate corners of the three components which will apply a force equivalent to the centrifugal force described above. A disadvantage of this puzzle is that once the method of separating them has been learned, the challenge has been removed as no variations are possible.
Another version of the puzzle was designed by Professor, Lionel Penrose, and is sold by Pentangle Hampshire, England and is called "Pandora's Box". This version of the puzzle has a poker chip inside that says "Hope!" on it. This piece apparently serves as a reward for opening the puzzle, but it is also there to make the person working the puzzle believe that it is the only internal element. The fact is, there is a small metal dowel which locks the layers of the puzzle together so that nothing can be moved. The only way to open the puzzle is by holding the puzzle vertically and shaking it so that the pin can be positioned in the center layer. Solving this puzzle is more by luck than by skill on the part of the problem solver. Once completely disassembled, this puzzle is even more difficult to put back together.